Autopilot pitch mode question

Hello! This has annoyed me for some time, but I'm just getting around to asking. Most aircraft, you can set an altitude in the autopilot, engage the AP in altitude hold mode, and it will climb to the set altitude at the default vertical speed. Fine; I like it like that. But some are not like that; engage altitude hold mode and it will hold the current altitude and override the preset altitude. I've tried to change this behavior and can't find a way. Using a different autopilot gauge on the panel will not help. I've tried settings for the autopilot in the aircraft.cfg, without success. There's settings there that look applicable, but they do nothing; I suspect they apply to FSX only and not fs9.

Any ideas?

Nadlzfw

If for example you set the altitude to 10000ft does it climb to 10300 then come back down lower then climb back up till it eventually settles or does it disengage completely?

If it fluctuates then settles I've had aircraft do that and others climb then start to settle when they get near the set altitude.

It applies to a few aircraft, not many. Right now, DHC-8Q400. Also, Embraer Xingu comes to mind. I think also my Curtiss C-46 does this. Plus 2 or three others than I don't recall specifically.

Scenario is this: I set 12000 in the autopilot, fly manually to 7000, then engage the autopilot and altitude hold. It immediately levels off at 7000 and the set altitude changes to 7000. I can change the altitude set in the AP to whatever I like, and it will climb/dive to that altitude, but it's a nuisance.

Nadlzfw

You might take a look in you plane's aircraft.cfg file for the section labeled [Autopilot] and a line under that that that reads default_pitch_mode=X, where X is a 0, 1, or 2. If it is a 2 is will hold the current altitude when the AP is first turned on. If it's a 1, it will hold the current pitch, if it's a 0 neither will occur. If it IS a 2, change it to the 0 and see if that cures your problem.

REMEMBER!!!! MAKA A BACKUP BEFORE editing ANY file.

Easiest way to do this is to LClick on the file before you start, then RClick on the same file, select COPY from the pulldown menu you get, and then RClick it again, go to an empty place in the folder you're in and RClick again, then click on PASTE. You will now have a file file named aircraft_COPY.cfg.

If you need to restore the original, because a change you make messes things up badly somehow, just delete the file you HAVE edited up to that point then rename the copy to aircraft.cfg again.

I am not trying to be insulting to your skill or intelligence, I just don't know what your skill level is at this point on editing FS9 files, and better safe than sorry :D

Just a possible fix for the problem you describe. Applies to any aircraft.

Pat☺

Well, the line 'default_pitch_mode' seems to have no effect, regardless of whether it is 0, 1 or 2. I tried that before, and now once more; no effect. That's what I alluded to in the original post, wondering if this line works in FSX but not FS04.

To Phantom Tweak: Thanks for the advice to back up. Don't need it, always do anyway, usually by adding prior values after '//'. But you are right; always good advice. And, don't worry about someone having a snit over unneeded good advice...such a person isn't worthy of this forum anyway.

Scenario is this: I set 12000 in the autopilot, fly manually to 7000, then engage the autopilot and altitude hold. It immediately levels off at 7000 and the set altitude changes to 7000. I can change the altitude set in the AP to whatever I like, and it will climb/dive to that altitude, but it's a nuisance.

Try engaging using the keyboard (Ctrl-Z) rather than with the mouse and I think you will be OK.

John

---------------------------------------------------------------------------------------------------

If you just want to set your AP Alt Hold to PRESENT alt, press 'Z' to engage

the AP, then press 'Ctrl+Z' to tell AP to set Alt to PRESENT Alt. This will also

set your pitch trim.

---------------------------------------------------------------------------------------------------

to 'update' the autopilot (capability) enter these lines in cfg's (autopilot) section:

use_no_default_pitch= 1 //0=Deft to current pitch mode //1=No def pitch mode

use_no_default_bank= 1 //0=Def to Wing Leveler mode //1=No def

default_pitch_mode=0

default_bank_mode=0

Chuck B

My apologies, I forgot about those two entries. Mind like a steel sieve...

Pat☺